REDHOTGEN 2 — Result In Brief

EU-funded researchers studied the genetics behind apple skin colour, which is negatively affected by warm temperatures typical of producing countries of South Europe. They found a way to identify new cultivars able to produce high skin colour apples even in those warm environments.

Southern Europe hosts major apple-growing regions, but warm climates and/or warming climate scenario, negatively affects their skin colour and quality, reducing fruit growers' economic returns. The most efficient and sustainable way to overcome this challenge is to identify new apple cultivars that are able to develop good skin colour in warm climates.

Scientists from Spain, Italy and New Zealand on the basis of an EU-funded REDHOTGEN 2 (Genetic and physiological regulation of skin red colour development on apples under high temperature environments: Genetic tools for developing heat tolerant red-skinned apples) project used molecular genetics to understand the cellular processes behind skin colour in apples.

By comparing the colour of apples grown in cool and warm areas (New Zealand vs Spain, respectively), they found that temperature affects concentrations of a skin colour pigment (anthocyanins) in the fruit. Through further research, the team established that warm temperatures down-regulate the activity of genes that control synthesis of this pigment. Based on this gain of knowledge, they developed genetic markers and implement them for marker assisted selection or MAS in a breeding programme. This will be a useful tool to select the cultivars of future able to produce high colour fruits even in warm climates. These new heat-tolerant apple cultivars will help farmers to be more competitive by providing a better adaptation to climatic change.

REDHOTGEN 2 used a number of different genetic tools to better understand the role of pigment-synthesising enzymes in controlling skin colour. This improved understanding will help with future breeding projects. This because they identified genetic markers linked to red skin colour in apples. Breeders will be able to use these molecular markers for MAS (marker assisted selection) to identify apple seedlings that will be able to produce high-quality red fruit in warm environments, like southern Europe and also these new cultivars could be expanded to other continents with similar weather conditions.

The markers that this project identified will help to speed up breeding programmes/breeding progress and ultimately improve livelihoods and profit for farmers.